Lessons from the past: predicting the tropicalisation of marine communities

Global climate change is warming temperate coastal waters, causing ecological disturbances and range shifts of marine organisms. Recently, hermatypic corals (reef-building corals) have expanded poleward into temperate regions of Japan in so-called ‘tropicalisation’ events. While this expansion offers hope that temperate areas could serve as refugia for corals under future climate change, it leads to the displacement of local fauna, causing range retractions for temperate species. Whether this coral expansion is a net benefit for biodiversity by fostering new reef ecosystems in temperate zones remains uncertain. This project will integrate past and present coral distribution data with climatic and ecological niche modelling to predict suitable coral habitats across time. By developing present-day ecological niche models and projecting them to past warmer intervals (e.g. mid-Holocene and Last Interglacial), potential areas of past tropicalisation will be identified. These areas will be validated against fossil records from fieldwork and pre-existing collections to refine models and improve projections under warming scenarios. Dispersal modelling will also be used to distinguish suitable and accessible habitats. The project aims to improve our understanding of coral range shifts, providing robust predictions of future habitat under climate change. Insights from this research will guide marine conservation strategies and evaluate temperate regions' potential as coral refugia.